This invention relates generally to magnetic drive systems, and more specifically concerns a power (torque) conversion system using magnetic action between a drive member such as a motor and a driven member such as a machine, including a drive shaft for the wheels of a vehicle.
Various arrangements are known which couple a drive assembly such as a motor and specifically the motor shaft to a machine shaft which is used to drive various mechanisms, including mechanical devices, such as a pump or the wheels of a vehicle, referred to as a driven assembly.
Most of these coupling arrangements are completely mechanical, using various gear and clutch arrangements. Various control arrangements are used to assist in the efficient coupling of the drive assembly to the driven assembly, including both mechanical and electronic devices.
A primary disadvantage of mechanical coupling arrangements is that the mechanical parts tend to wear and eventually break; the mechanical arrangement can also be complex, in both the number and the type of parts required. Also, conventional systems are usually inefficient, because the motor does not run consistently at its most efficient speed; the driven assembly/machine must operate under varied conditions of torque as well as speed. The motor is controlled, with various gear ratios, to satisfy the varying requirements of the driven assembly.
One attempt to overcome the disadvantages of a purely mechanical coupling is a magnetic coupling arrangement between the motor (the drive member) and the driven member. An example of such a magnetic coupling using two discs in registry is shown in U.S. Pat. No. 5,668,424 to Lamb et al, as well as several other patents to Lamb. However, such magnetic coupling arrangements have their own disadvantages, in that rather complicated control mechanisms must be used to control the physical distance between the magnetic coupling elements. Further, the power capacity of such existing systems is increased only by increasing the diameter of the two discs, which has practical limitations in most systems.
A magnetic coupling system, which would overcome the above disadvantages of existing magnetic, coupling devices, would be advantageous in many applications.
Accordingly, the present invention in one aspect is a magnetic drive differential system for a vehicle, comprising: a driving assembly, which is driven by a vehicle motor, which is in turn connected to a motor shaft, wherein the driving assembly includes two electrically conductive cylinders, each having a selective length; and a coupling structure which includes first and second ring-shaped assemblies of permanent magnets operating independently of each other, in association, respectively, with the two electrically conductive cylinders, the coupling structure further including first and second axle shafts to which the permanent magnet assemblies, respectively, are mounted, such that rotation of the motor shaft results in the independent rotation of the axle shafts, wherein vehicle wheels are mounted at the free ends of each axle shaft, the vehicle wheels thus operating independently of each other in response to motor action.
The present invention in another aspect is a magnetic drive differential for a vehicle, which comprises: a driving assembly, driven by a vehicle motor, wherein the driving assembly includes first and second pairs of concentric permanent magnet ring-shaped assemblies with a defined space between them; and a machine assembly, including first and second axle members which have wheels mounted thereon, each axle member including a mounting element having an electrically conductive cylinder extending therefrom, each electrically conductive cylinder configured, respectively, to fit between and come into a magnetic relationship with one pair of permanent magnet assemblies, wherein actuation of the driving assembly by the vehicle motor results in driving of the vehicle wheels.